Upload & Sell: Off
Have acquired a used 100/2 ZE as well. Infinity doesn't seem to be on with the lens marking (fair enough but it'd sure be easier if it was - do Zeiss recalibrate lenses for infinity?) and I'm finding a lack of contrast on a lot of f/2 shots. Is that to be expected?
Canon body tolerances are so gigantic that there Zeiss can't calibrate their lenses to infinity. I had 3x 5DmkII and 1DmkIII and there wasn't any camera which would have had infinity exact same as any other camera...
There have been cases, when there have been issues with Zeiss ZE lenses that Zeiss could not calibrate without having also camera (e.g. ZE21) to user satisfaction. So I would assume you could ask Zeiss to calibrate for infinity, but then your lens would be calibrated in temperature Zeiss has in their laboratory - depending lens design focus would be either too far or too close in any other situation than Zeiss laboratory situation. For some longer focal length lenses it's known fact that lens should go well past infinity to compensate temperature changes.
PS. In digital era the hard infinity stop is useless, there is no way I would ever trust it with digital. It might have been useful on film era, but I really can't see how it would work in real field shooting for 36+Mpix.
For 2/100 contrast wide open; yes it improves a lot closing down to f/2.8. I mostly shot it f/2.8-4 as best compromise between DOF and optical issues (aberrations, boke quality, contrast).